Sudoku League League of online competitors. Scoreboard, rules, FAQ, hall of fame, and instructions. [English/Czech] http://www.sudoku-league.com/ Sudoku-league.com~Site InfoWhoisTrace RouteRBL Check
Web Sudoku Free puzzles with difficulty levels ranging from easy to evil. Provides print and online syndication. http://www.websudoku.com/ Websudoku.com~Site InfoWhoisTrace RouteRBL Check
Sudoku Hints Offers daily web-based puzzles with five difficulty levels. Includes solver, helper, and XML feed. http://www.sudokuhints.com/ Sudokuhints.com~Site InfoWhoisTrace RouteRBL Check
Paul's Pages Offers random, crafted, and non-standard puzzles. Includes hints and import/export tool. http://www.paulspages.co.uk/sudoku/ Paulspages.co.uk~Site InfoWhoisTrace RouteRBL Check
Play Sudoku JavaScript-based Sudoku, available for syndication on other sites. http://www.geocities.com/binnyva/code/javascript/sudoku/ Geocities.com~Site InfoWhoisTrace RouteRBL Check